从3DES密钥计算KCV

Question

任何人都知道如何计算3DES密钥的校验值（KCV）吗？

示例键DBFE96D0A5F09D24的检查值为5B4C8BED

我看到了C＃的示例，但没有看到Java。

Answer 1

尝试以下很大程度上基于“ Calculating the Key Check Value of a key”文章中提供的代码的代码：

package javaapplication28;

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import java.security.GeneralSecurityException;
import java.security.Security;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import org.bouncycastle.util.encoders.Hex;

public class JavaApplication28 {

    public static void main(String[] args) throws GeneralSecurityException {

        String key = "DBFE96D0A5F09D24";
        byte[] bytes = key.getBytes();
        String kcv = JavaApplication28.getKcv(bytes);
        System.out.println("key=" + key + ", kcv=" + kcv);
    }

    // Heavily based on code provided in the article "Calculating the Key Check Value of a key".
    // https://hk.saowen.com/a/55c92a558ccb3e062970bab22eaa83c5c4d121878925c05f7949b988f61963e3
    private static String getKcv(byte[] key) throws GeneralSecurityException {
        // Add Bouncy Castle Security Provider
        Security.addProvider(new BouncyCastleProvider());
        // Construct a Secret Key from the given key
        SecretKey skey = new SecretKeySpec(key, "DESede");
        // Instantiate a DESede Cipher
        Cipher encrypter = Cipher.getInstance("DESede/ECB/NoPadding", "BC");
        // Initialize the cipher with the key in Encrypt mode
        encrypter.init(Cipher.ENCRYPT_MODE, skey);
        // Encrypt an 8-byte null array with the cipher and return the first 6 Hex digits of the result
        return Hex.toHexString(encrypter.doFinal(new byte[8])).substring(0, 6).toUpperCase();
    }
}

这是使用键值运行时的输出：

run:
key=DBFE96D0A5F09D24, kcv=F153C7
BUILD SUCCESSFUL (total time: 0 seconds)

注意：

1. 代码需要Bouncy Castle jar文件 bcprov-ext-jdk15on-160.jar ，您可以从此处下载：https://www.bouncycastle.org/example.html

2. 它不会不返回您指定的KCV。但是，它确实与使用在线验证器http://tripledes.online-domain-tools.com/时返回的值匹配，如下面的屏幕截图所示。